Filter housings according to the introduction are known from filtering devices for certain laboratories or the like in which there is a risk that the ambient air will be contaminated. In order to prevent air from such environment to leak out, such laboratories often are set under sub-pressure. The function of the filter is to capture all infectious particles or other contaminations, such as bugs or other air carried infectious organisms, in the circulated air. There is thus a risk that the filter unit will contain dangerous contaminations after the filtering device has been in operation. Before changing a filter unit it must therefore be ensured that the possible contaminations captured therein no longer are dangerous to human beings. This is done by letting a decontamination gas pass through the filter unit in order to kill all bacteria or other infectious or contagious organisms or the like. It is therefore essential that the air or gas pass through the filter unit and not outside thereof. In order to ensure that air to be filtered or decontamination gas pass only through the air filter unit, sealing elements are arranged between the respective end of the filter unit and an end wall of the filter chamber and the clamping device, respectively.
However, the persons changing taken out a used filter unit and substituting the removed air filter unit by a fresh one are often dressed in uncomfortable protective clothing so that their movements are rather awkward and clumsy. There is therefore a great risk that the air filter unit or the sealing elements thereof be damaged during introduction of the unit into a filter chamber, especially if the air flow is vertical in the filter housing.
An objective of the present invention is to reduce the risk for damaging an air filter unit during introduction thereof into a filter chamber. Another objective is to facilitate introduction of and change of air filter units in a filter chamber in an air filter housing.